Chitosan Adhesive Films for Photochemical Tissue Bonding

Abstract

Photochemical tissue bonding (PTB) is a promising sutureless technique for tissue repair. PTB is often achieved by applying a solution of rose bengal (RB) between two tissue edges, which are irradiated by a green laser to crosslink collagen fibers with minimal heat production. In this study, RB has been incorporated in chitosan films to create a novel tissue adhesive that is laser‐activated. Materials and Methods. Adhesive films, based on chitosan and containing ∼0.1wt% RB were manufactured and bonded to calf intestine by a solid state laser (wavelength = 532 nm, Fluence ∼110 J/cm2, spot size ∼5 mm). A single‐column tensiometer, interfaced with a personal computer, tested the bonding strength. K‐type thermocouples recorded the temperature (T) at the adhesive‐tissue interface during laser irradiation. Human fibroblasts were also seeded on the adhesive and cultured for 48 hours to assess cell growth. Results and Conclusion. The RB‐chitosan adhesive bonded firmly to the intestine (15±2 kPa, n = 31). The adhesion strength dropped to 0.5±0.1 kPa (n = 8) when the laser was not applied to the adhesive. The average temperature of the adhesive increased from 26 °C to 32 °C during laser exposure. Fibroblasts grew confluent on the adhesive without morphological changes. A new biocompatible chitosan adhesive has been developed that bonds photochemically to tissue with minimal temperature increase.